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John Isner questionable for Davis Cup

John Isner is the top-ranked American man ahead of Sam Querrey. (Rob Griffith/AP)

John Isner may not be 100 percent when the U.S. opens its Davis Cup campaign against Brazil in Jacksonville, Fla., on Friday. Speaking to the Greensboro (N.C.) News-Record, Isner said the bone bruise in his right knee that forced him out of the Australian Open needs more time to heal.

“It’s something I felt a little in the offseason. I’ve had times in the past where some ache would nag me, but then go away. In hindsight, I should’ve been more cautious and not trained through it. But I didn’t do that. And it bothered me in Australia.”

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“It’s frustrating,” the Greensboro native said, “because it’s not a muscular problem you can rehab. It’s on the bone, so you just have to wait.

Right now, it's a race against the clock. Isner, scheduled to play singles on Friday against Brazil's No. 2, 141st-ranked Thiago Alvez, hopes to be ready in time.

“I can’t say if I’ll be 100 percent in three or four days,” Isner said. “I just don’t know. I’ll give it a try this week and see how it goes. I do know I won’t take any chances and risk the rest of the season. If I can play, I’ll play. If I can’t, I’ll wait.”